We use both fmod event system and fmod ex lower level, and we let the fmod api to handle the channel playback with FMOD_CHANNEL_FREE, so we need in channel callback a new type like in fmod event system FMOD_EVENT_CALLBACKTYPE_STOLEN, and in the setcallback a void* user data. I read about counted reference channels, that become invalid, but how can I manage it? How could I know it’s not valid, and should I delete the object? It isn’t clear enough for me.